checking every digit in a number for oddness
- by tryt
Hello. I was writing a function which checks if every digit in a number is odd. I came accross this weird behaviour. Why does the second function return different (incorrect) results, eventhough its basically the same? (implemented in an opposite way)
#include <stdio.h>
int all_odd_1(int n) {
if (n == 0) return 0;
if (n < 0) n = -n;
while (n > 0) {
if (n&1 == 1)
n /= 10;
else
return 0;
}
return 1;
}
int all_odd_2(int n) {
if (n == 0) return 0;
if (n < 0) n = -n;
while (n > 0) {
if (n&1 == 0)
return 0;
else
n /= 10;
}
return 1;
}
int main() {
printf("all_odd_1\n");
printf("%d\n", all_odd_1(-131));
printf("%d\n", all_odd_1(121));
printf("%d\n", all_odd_1(2242));
printf("-----------------\n");
printf("all_odd_2\n");
printf("%d\n", all_odd_2(131));
printf("%d\n", all_odd_2(121));
printf("%d\n", all_odd_2(2242));
return 0;
}
